All we know is that the Relic Crown and other treatures were made by the civilization some 3,000 years ago.Originally Posted by Kameinu
That war ended with neither side winning, Unova being destroyed, and Reshiram and Zekrom "dying". I don't see how the writings could be a reference to that event.But the writtings could very well tell of the events that led to the end of the second war. Maybe a prophecy of sorts for then. King ends the reign of the twin heroes family and starts a new reign, which the Harmonia lineage comes from. The people of the war era could've been aware of the writtings.